Heating apparatus



Oct. 24, 1944. Q H 2,361,097

HEATING APPARATUS Filed March ll, 1941 INVENTOR E'Ffazmc 0. H555 51WATTORNEY Patented Oct. 24, 1944 HEATING APPARATUS Frederico. Hess,Germantown, Pa., assignor to Selas Corporation of America, a corporationof Pennsylvania Application March 11, 1941 Serial No. 382,771 3 Claims.(Cl. 126-92) The general object of the present invention is to providean improved gas burning heater adapted for use in heating rooms orspaces which may advantageously be heated by a gas burning heatersuspended in the upper portion of the room or otherwise supported in thegeneral manner in which lighting fixtures are suspended or supported.

In its preferred form-the improved heater comprises an upper bowl-shapedmember of refractory material and a lower bowl-shaped shell or sheetmetal member, the two members being in nesting relation, but spacedapartto form a combustion space having top and bottom walls, respectivelyconcave and convex, and includes a gas burner in such space creatingflame jets which extend away from the heater axis at points distributedabout the latter, and which are generally tangential to the adjacentportions of the refractory bowl which is thereby heated to in-'candescence. A substantial portion of the heat liberated in thecombustion space is transmitted to the space to beheated by radiationfrom the metallic bowl, and a major portion of the remainder of theheat'liberated is transmitted to the atmosphere in the space to beheated which is in contact with the metallic shell and is there bysubjected to a convection heating efiect. The improved heater ischaracterized by its mechanical simplicity, the relatively low cost atwhich it can be manufactured and installed, and by the substantialheating capacity obtainable with a heater of convenient'bulk, comparablewith that of an ordinary indirect electric lighting fixture, and by thenovel character of its gas burner element.

For some uses, the supply of gas to each heater may be controlledmanually, as by means of an to the heater, when contamination of theroom atmosphere by the heating gases is objectionable from theventilation standpoint, or because of the possible adverse action oncertain metal treating or other work operations carried on in the roomheated.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, its advantages, and specific objects attained with its use,reference should be had to the accompanying drawing and descriptivematter in which I have'illustrated and described a preferred embodimentof the invention.

Of the drawing: I

Fig. 1 is an elevation of a heater and associated gas supply and controlparts;

Fig. 2 is a partial section taken on the line 22 of Fig. 1; and r Fig. 3is a section on the line 3-3 of Fig. 2.

The heater structure shown in Figs. 1, 2 and 3, comprises a bowl-likerefractory body A of ceramic material, a gas burner B, a combustionchamber 0 crescent-shaped in section and having upwardly-extendingsides, and a heat radiating bowl-shaped member D of sheet metal whichforms the lower wall of the chamber C, the upperwall of the latter beingformed by the bowl .A. The burner B is located within the space C and asshown is coaxial with the bowl A, and has orifices delivering flame Jetsdistributed about and extending away from the common vertical axis ofthe bowl and burner, and generally tangential to a convex imperforatesurface zone of the bowl A, surrounding and displaced a shortdistancefrom said axis. cured at its upper end edge, as by screws D, to adepending rim flange portion E of a heater top member E. The member D isformed with a central air inlet opening D and D represents a shield orshade larger in diameter than "the opening D and normally held somedistance below and coaxial with said opening by spring fingers Dengaging the member D at the margin of the opening D The member E isformed of metal and as shown comprises a centra1 hub portion E anapertured body portion and radial stifiening ribs E The body portion ofthe member E is advantageously lined by non-metallic heat insulatingmaterial F.

The products of combustion formed in the combustion chamber 0 issue fromthe latter into the insulated space between the bowl A and the topmember E, through ports A" extending through the bowl A adjacent itsupper edge. The

products of combustion pass awayfrom the last mentioned space throughone or more outlet ports F' formed'in the member F. Each port F may opendirectly to the space in which the As shown, the member D is seheater islocated, when the heater is used in a room, shop or factory in .whichthe escaping products of combustion may be discharged into the roomatmosphere without objectionable consequences, but when desirable, theproducts may be discharged into a vent pipe 1 leading. out of the spacein which the heater is located.

The heater is supported by a vertically dismember I from a normally openposition into a a closed position.

The valve I is moved into its closed position by a thermostatic element'J, when the latter cools as a result of the extinction of the flame ofa pilot burnervK. The thermostatic element J is a bimetallic disc havingits center connected to the stem I of the valve I', and having itspeposed tubular element or pipe member G. As

shown, the member G mechanically connects the bowl A and the top memberE. To this end, the

member G'is formed with a collar G engaged I by the lower end of the hubE, and has a threaded upper end portion extending through the hub E, onwhich is threaded an end member G between which and the collar G the hubFl is clamped. At its lower end, the member G is provided with anout-turned flange G in supporting engagement with an annular portion ofthe bowl A, surrounding the central aperture therein through which themember G extends.

' flow of gas into the chamber B when the flame The burner B in thepreferred form illustrated comprises a metal casting formed with acentral threaded seat B at its upper side into which is threaded thelower end of a gas pipe I. The latter is threaded at its upper end intothe part G which connects the pipe I to a suspension and of the pilotburner K is extinguished. To this endthe disc J is arranged so that whenhot its upper side is convex and it holds the valve I in its openposition, and when the disc J cools it snaps into the position in whichits upper side is concave and in which it holds the valve 1' in itsclosed position. In normal operation the disc J holds the valve I in itsopen position in consequence of the conduction of heat to the disc gassupply pipe IA. The burner casting is formed with a gas inlet chamber 3in open communication with the bore of the pipe I and which in normaloperation is in free communication with a subjacent gas outlet chamber3. The cylindrical outer wall of the chamber 133 is formed with aplurality of small radially extending discharge orifices B". Each burnerorifice B is coaxial with a corresponding mixing nozzle passage b in anannular mass of ceramic material surrounding and spaced away from thedischarge ends of the orifices B In the preferred construction shown,the ceramic material mass comprises two annular ceramic bodies b, whichmay be counterparts of each other. Each part b is formed witha circularseries of raised bosses or lugs b which abut against the correspondingbosses or lugs b of the other part b, when the two parts are assembledas shown in Fig. 2. The bosses or lugs 12 form the side walls of theorifices b. The bosses b of each member b and the surface of the latterfrom which the bosses project are shaped to give each orifice b' theshape of a venturi channel which is flattened, so that its transversedimensions in the direction of the plane of the engaging ends of thebosses b are greater than its transverse dimensions in a directiontransverse to such plane. As shown the ceramic parts b are held in placein the burner structure by screws b extending through the parts and eachthreaded into a correspondin radial arm B of the burner casting whichextends between the lower end of flange G of the member G and the upperside of the upper burner part b.

Each arm B is formed with an uprising projection 13 adjacent its outerend, which directly engages the flange G and spaces the body of the arm3* away from said flange so as*to limit the J by the disc support J andan armJ' thereof which extends into position to be heated by the flameof the pilot burner K.

The metallic parts of the burner B are protected against overheating bythe cooling action of air drawn past the burner casting into themetallic pipe G by the chimney action of the latter which opens to theatmosphere at its upper end through portsG in the member G The airrequired for that cooling action andthe necessary combustion air enterthe space C through the bottom opening D in the metallic member D andusually some additional air is drawn through the opening D into thespace 0 and is moved through the space 0 by the chimney action of saidspace. If, as will probably be the case in most uses of the heater, theproducts of combustion are discharged directly into the space heatedthrough the outlet ports 1'', the heat carried out of the heater by theproducts of combustion is directly utilized in heating said space.

In many cases, my improved heater units may be expected toreplaceindirect lighting or other pose of encasing the supply conductors forthe lamps. The latter are located a few inches above the top surface ofthe heater top member E. The pipe'IA also supports a light diffusingmember M which may be a translucent glass disc, and is located a fewinches above the lamps L. Advantageously the top surface of the memberEA is polished, in some cases, it may well be a chromium plated surface.The provision of the polished heater top surface not only insuresadequate light reflecting capacity, but tends to a reduced rate of heatradiation from the top of the heater. light diffusion member M also actsto reduce heat The.

heat insulation material F.

heater, as does the radiation from the top of the In the normaloperation of the heater shown by Figs. 1, 2 and 3, each burner castingorifice B and the corresponding ceramic. material channel 12' coact toeffect the typical Bunsen burner ac- I tion. The-gas jet dischargedthrough the orifice 3* toward and in the axial direction of the passageb induces a flow into the latter of air which mixed with the gas in thepassage b constitutes, with suitably proportioned apparatus, all or amajor port.on of the air required for the combustion of the gas withwhich it is mixed. The air inducing action of the Jet discharged throughI each orifice B may be augmented by providing the latter with a nozzleextension, formed as shown by a corresponding radial projection at theouter side of the wallof the chamber B The horizontal flattening of thepassages b and particularly of the expanding discharge nozzle portion ofthe passage, has the eflect of flattening the burning jet extending awayfrom the periphery of the annular ceramic body b, b, and of therebyincreasing the heat radiation from the flame to the refractory body A.

In consequence of the fact that the channels b are surrounded byrefractory material and of the further fact that the'jets of air andgaseous fuel mixture are discharged from the ports of the channels atregions alongside of and underlying the outer surface of the refractorymaterial A, a substantial portion of the heat liberated by the flamesproduced by the jets is radiated to closely adjacent imperforate regionsof the member A. This makes it readily possible to heat the mem- A, theportion of the latter immediately adjacent the burning jets is notcooled as it would be if the unbumt jet material impinged against saidrefractory member. In consequence, the temperature of the refractorymaterial adjacent the jets is high enough to insure highly efficientcombustion conditions, and the maintenance of gas temperaturesthroughout the combustion space high enough to insurethat substantiallyall of. the convex surface of the refractory member A is heated toincandescence. In consequence, all portions of the metallic shellD'receive heat by radiation at a relatively high rate from. thererefractory member A, as well as by conduction from the gases in thespace C. The entire outer surface of the shell D is thus adapted toradiate heat at a relatively high rate.

The metallic shell D receives heat by radiation from the more highlyheated refractory bowl A and has its lower portion cooled and its upperportion heated by the air and gas flowing through her A to incandescenceand to maintain high flame temperatures, whereby good combustionefilciency and a relatively large heat producing capacity Per unit ofheater bulk are obtained.

With the approximately hemispherical form of the metallic member D, thedistribution of the heat radiated by the heater is especially suitablefor use in heating a room when the heater is suspended from the roomceiling. The relatively high combustion chamber temperature permits ofemcient combustion with little or no excess air. A reduction in excesscombustion air contributes directly to the maintenance of highcombustion chamber temperatures and of a high thermal emciency. Vmtended regular use of heaters constructed in accordance with thepresent invention have shown them to be practically effective,efficient,

and reliable in operation. Merely byway of ilthough having a topdiameter of about 20 inches,

is adapted to liberate heat at a rate of approximately 40,000 B. t. asper hour, when ordinary town gas of about 500 B. t. u. value is suppliedto the space 0. This tends to reduce the total heat absorption by themember D, which receives radiant heat from the more highly heated lowerportion of the bowl A, relative to the heat absorptlon by the upperportion of the member D. This tendency to equalization of thetemperature of difl'erent'portions of the member D is practicallyadvantageous in that it tends to increase, rather than to decrease, theamount of heat radiated radially away from the member D while at thesame time desirably reducing the heat radiation from the lower centralportion of the member D which otherwise might be more intense than isdesirable in many cases. I

As shown, though not essential, the refractory member A is formed in onepiece and the thickness of the combustion space C diminishes in agenerally uniform manner from the bottom of the space to its upper edge,so that theflo'w path for the heating gases maybe approximately uniformin'cross section from the burner to the outlet ports A.

the burner mixer, and to discharge heating gases through its outlet portor ports F at atemperature of about 500 F. As those skilled in the artwill recognize, that low heating gas exit temperature necessarily meansa relatively high heater efficiency.

The relatively high efficiency, and large capacity perunit of spaceoccupied by the improved heater, are due primarily, I believe, to thetemperature and combustion conditions prevailing in the combustion spaceC. Owing to the tangential disposition of the flame jets close to thelower central portion of the refractory member Preferably, and as shown,the member A has its convex under surface formed with grooves Aextending circularly about the vertical axis of the heater. Suchroughening of the convex surface of the member A adjacent the burnerincreases he heat absorbing of the burner and facilitates themaintenance of combustion.

To prevent back-firing inv the passages .b' I

may advantageously provide the burner with a fire screen, which, asshown in Fig. 2, is in the form of a short cylinder of wire netting Qhaving its upper and lower edges received in circular grooves b in eachof the 'annular ceramic bodies b adjacent its periphery extending intothe latter from its face adjacent the other body. This .application is acontinuation in part of and supersedes my earlier application, SerialNo. 246,321, filed December 1'7, 1938.

While in accordance with. the provisions of the statutes, I haveillustrated and described the best form of embodiment of my inventionnow known to me, it will be apparent to those skilled in the art thatchanges may be made in the form of the apparatus disclosed withoutdeparting from the spirit of my invention, as set forth in the appendedclaims.

Having now described my invention, what I claim as new and desirePatent, is:

1.-A heater adapted to radiate heat into a space to be heated,comprising a combustion to secure by Letters and heat radiating capacitychamber having a thin metallic heat radiating outer wall of hollowapproximately semigiobular form, and having an inner wall of refractorynon-metallic material and of globular form and adapted to radiate heatto substantially all portions of said outer wall along linessubstantially perpendicular to the latter and a burner centrally locatedin said chamber and formed with orifices and adapted to dischargecombustible fluid into said combustion chamber in jets directed awayfrom the burner axis and an annular body of ceramic material surroundingsaid burner and formed with mixing nozzle passages respectively coaxialwith said orifices and respectively adapted to receive said jets and airstreams induced by said jets and to discharge air and gas mixture jetsadjacent and generally tangential to corresponding portions of therefractory inner wall of the combustion space.

2. In an improved heating apparatus, the combination of an inner heatradiating bowl of refractory material and an outer heat reflecting bowl,said inner bowl being nested within said outer bowl to form a chambertherebetween, said chamber beingcrescent-shaped in section and havingupwardly extending sides, a centrally disposed burner mounted in thelower part of said chamber and having a plurality of discharge portsclosely adjacent to the outer surface of said inner heat radiating bowl,means whereby said burner is adapted to receive a mixture of air andgaseous fuel, said burner being constructed and arranged to dischargeradially outward from said ports a plurality of jets of the air andgaseous fuel mixture at regions alongside of and underlying the outersurface of said inner bowl, the lower part of said inner bowl beingimperforate at the regions alongside of which the jets are discharged,said jets being adapted to be ignited to produce flames from which heatis radiated to the closely adjacent imperforate regions of said innerbowl to heat the latter to incandescence, the heat radiated from saidincandescent regions of said inner bowl being eflective to promotecombustion of the jets and maintain high flame temperatures.

3. In an improved heating apparatus, the combination of an inner heatradiating bowl of refractory material and an outer heat reflecting bowl,said inner bowl being nested within said outer. bowl to form a chambertherebetween, said chamber being crescent-shaped in section and havingupwardly extending sides, said inner bowl having a central opening inthe lower part thereof, a centrally disposed burner in the lower part ofsaid chamber, said burner having a plurality of discharge ports closelyadjacent to the outer surface of said inner heat radiating bowl, pipingextending downwardly through said inner bowl in alignment with theopening and having the lower end thereof connected to said burner. saidouter-bowl having an opening at the vicinity of said burner, meansincluding said piping whereby said burner is adapted to receive amixture of air and gaseous fuel, said burner being constructed andarranged to discharge radially outward from said ports a plurality ofjets of the air and gaseous fuel mixture at regions alongside of andunderlying the outer surface of said inner bowl, the lower part of saidinner bowl being imperforate at the regions alongside of which the jetsare discharged, said jets being adapted to be ignited to produce flamesfrom which heat is radiated to the closely adjacent imperforate regionsof said inner bowl to heat the latter to incandescence, the heatradiated from said incandescent regions of said inner bowl beingeffective to promote combustion of the jets and maintain high' flametemperatures, and said chamber having one or more openings at the upperpart of the upwardly extending sides through which products ofcombustion are discharged from said chamber.

FREDERIC o. HESS.

